The inetics of mineralization of calcium phosphates and the inorganic and organic components of teeth such as whole and carious enamel, dentin, calculus, unerupted teeth and organic phases suh as collagen and elastin will be studied at constant super-saturation. Measurements will be made over a range of ionic strength, concentration and pH typical of those in the mouth. The influence oif anti-caries and anti-calculus agents and crystal growth inhibitors will be investigated as well as changes in surface portential and the state of aggregation of the mineralizing phases. The kinetics of formation of early lesions such as white spots on bovine and human enamel will be studied using the same constant composition (CC) method developed in our laboratory. Subsequent CC remineralization of these white-spots will be made and the lesions will be characterized by electron microprobe and x-ray microradiographic analysis. The development of effective methods for remineralizing the lesion will be emphasized and the studies will be made in the presence of crystal modifying and cariostatic agents. The effect of carbonate and readily incorporated ions such as strontium will also be examined by the CC method. In parallel with these studies, solid minreralized phases will be characterized by scanning electron microscopy, electron microprobe, infrared, x-ray diffraction, specific surface area, particle size and surface charge analysis. CC dissolution kinetic measurements will be made using the well-defined hydrodynamics of the rotating disc to provide a model for in vivo tooth surface and sub-surface erosion.